2d6 method is 0.275 hit points per round behind standard

1d12 method is 0.239 hit points per round behind 2d6 method and 0.514 hit points per round behind standard.

This, of course, assumes that my spreadsheet formulas are correct (I’ve gone over them again to make sure I didn’t mis-think anything) and that Excel’s randbetween function is truly random.

I used a d6+d6 for the 2d6 option, and a d12 for that option, basing both of those attacks on the first claw roll. So if claw 1 hit, so did the 2d6 and the d12 method. If claw 1 missed, so did 2d6 and d12 methods. My reason for this was that I didn’t want one of the options to “roll good” or “roll bad” relative to the standard method for to-hit and throw things off a bit. I’m looking at replacing 3 to-hits with 1, so I took the first to-hit and pretended that it was the d20 roll either for the first claw or for the whole attack.

I did this 1000 times and totaled the total damage for each method, then divided by 1000 to get the average points of damage per attack per method. It’s not a prediction of what should happen, it’s a report on what did happen. Every time I run it the totals are slightly different, but not by much.

I expanded it to 10,000 attacks and here are the totals
3.714 standard
3.495 one attack for 2d6
3.256 one attack for 1d12

I did it again (10,000 more attacks) and here are those results:
3.779 standard
3.478 one attack for 2d6
3.238 one attack for 1d12

Again:
3.709 standard
3.403 one attack for 2d6
3.166 one attack for 1d12

(I just showed multiple runs to demonstrate the typical variability.)

Claw/Claw/Bite
(%to hit x avg. claw dam) + (%to hit x avg. claw dam) + (%to hit x avg. bite dam)

Combined damage 2d6
(%to hit x avg dam on 2d6)

Combined damage 1D12
(%to hit x avg. dam on 1d12)

Option #2 would on average score more than option #3 (because average damage for 2d6 is 7 and average damage for 1d12 is 6.5). Option #1 SHOULD score higher than either (I think…I haven’t done the math)…but not if you use the same to hit roll for ONE of the option #1s attacks as the to hit roll for the other options.

HOWEVER, that being said, I think you’ve demonstrated that any effect is minimal…and as such, if combining damage into one roll speeds up your combat, go for it! You’re the DM after all…I’d suspect players would only complain if you tried to combine THEIR multiple attacks.

: )